Most scientists agree that black holes exist but are nearly impossible to locate.A black hole in the universe is not a solid object,like a planet,but it is shaped like a sphere （球体）.Astronomers（天文学家）think that at the center of a black hole there is a single point in space with infinite（无限的）density（稠密）.This single point is called a singularity （奇点）.If the singularity theory is correct,it means that when a massive star collapses,all the material in it disappears into the singularity.The center of a black hole would not really be a hole at all,but an infinitely dense point.Anything that crosses the black hole is pulled in by its great gravity.

Although black holes do exist,they are difficult to observe.These are the reasons.

● No light or anything else comes out of black holes.As a result,they are invisible to a telescope.

● In astronomical terms,black holes are truly.For example,a black hole formed by the collapse of a giant star would have an event horizon（视界）only 18 miles across.

● The nearest black holes would be dozens of light years away from Earth.One light year is about 6 trillion（万亿）miles.Even the most powerful telescopes could not pick out an object so small at such a great distance.

In 1994 the Hubble Space Telescope provided evidence that black holes exist.There are still answers to be found,however,so black holes remain one of the mysteries of the universe.

16.Black holes are part of space.

A.Right B.Wrong C.Not mentioned

17.Black holes exist but are difficult to observe.

A.Right B.Wrong C.Not mentioned

18.The center of a black hole is empty.

A.Right B.Wrong C.Not mentioned

19.The attraction of two large stars leads to gravity.

A.Right B.Wrong C.Not mentioned

20.The sun is the heaviest star in the universe.

A.Right B.Wrong C.Not mentioned

21.The nearest black holes are hundreds of light years away from us.

A.Right B.Wrong C.Not mentioned

22.The Hubble Space Telescope helps scientists to understand the nature of the universe.

1A project to unlock secrets-what scientist could resist that challenge?This is what many scientists are doing as they work on the Human Genome Project.The aim of the project is to decode（破译）all of the some 100,000 genes in the human body.Scientists are using DNA fingerprinting techniques to do the decoding.

2DNA is the substance found in the chromosomes（染色体）of a cell.A chromosome is a chain of genes.Each gene carries a piece of genetic information.At any one moment in a cell,thousands of genes are turned on and off to produce proteins（蛋白质）.The challenge for scientists is to find out what role each gene plays in protein production.At some point this decoding will be complete.Then scientists will have a map of an ideal genome,or a picture of the total genetic nature of a human being.The ideal genome is called a consensus（交感）genome.Everything works well in a consensus genome.

3But no one in the world has a consensus genome.Everyone's genome is different from the ideal.These differences are referred to as genetic mutations（突变）.Genetic mutations in a person's genome mean that the person has a greater than average chance of suffering from health problems.Some problems are not life-threatening.These would include things like colorblindness,or mild headaches.Other problems are serious,such as heart disease,or cancer.

4It will take years to identify the role of each of the 100,000 genes,The short-term goal of the project is to find the physical and mental health problems a person is likely to encounter during his or her lifetime.The long-term goal is to have each person live a longer,healthier life.

23.paragraph 1. 24.paragraph 2. 25.paragraph 3. 26.paragraph 4. A How does DNA work? B What is the Human Genome Project about? C How are the DNA samples collected? D What are the goals of the Human Genome Project? E What is the role of each gene? F What are the consequences of genetic mutations?

27.The Human Genome Project is trying to map allthat make us human. 28.Decoding the human genome is a challenge to. 29.Genetic mutations in a person's genome may affect. 30.Scientists are trying hard to discoverof each of the genes in our body. A that person's health B a scientific answer C scientfic researchers D the genes E the function F the size

第4部分：阅读理解（第31~45题，每题3分，共45分） 下面有3篇短文，每篇短文后有5道题。请根据短文内容，为每题确定1个最佳选项。

第一篇

Motoring Technology

1.2 million road deaths worldwide occur each year,plus a further 50 million injuries.To reduce car crash rate,much research now is focused on safety and new fuels-though some electric vehicle and biofuel research aims at going faster.

Travelling at speed has always been dangerous.One advanced area of research in motoring safety is the use of digital in-car assistants.They can ensure you don't miss important road signs or fall asleep.Most crashes result from human and not mechanical faults.

And improvements to seat belts,pedal（脚踏）controls and tyres are making driving smoother and safer.The colour of a car has been found to be linked with safety,as have,less surprisingly,size and shape.

But whatever is in the fuel tank,you don't want a thief in the driving seat and there have been many innovations（创新）.Satellite tracking and remote communications can also come into play if you crash,automatically calling for help.

Accidents cause many traffic jams,but there are more subtle interplays between vehicles that can cause jams even on a clear but busy road.Such jams can be analyzed using statistical tools.Robotic drivers could be programmed to make traffic flow smoothly and will perhaps one day be everyons's personal chauffeur（司机）,but their latest efforts suggest that won't be soon.

33.Which of the following safety developments is NOT mentioned in the passage? A.Windscreens that can help drivers to improve their vision. B.Radars that can help drivers to see obstacles in fog. C.Devices that can help drivers to see through big vehicles. D.Improvements in seat belts,pedal controls and tyres.

34.Satellite tracking and remote communication systems cna be used to A.reduce oil consumption. B.remove the obstacles on the road. C.call for help when one's car crashes. D.help drivers get out of a traffic jam.

35.Which of the following statements is true of robotic drivers? A.It will take some time before robotic drivers are available. B.Robotic drivers are not allowed to driveon busy roads. C.Robotic drivers can never replace human drivers. D.Robotic drivers are too expensive to use.

第二篇

Good Table Manners

Manners play an important part in making a favorable impression at the dinner table.Here are some general rules:

Napkin（餐巾）use

The meal begins when the host unfolds his or her napkin.This is your signal to do the same,so place your napkin on your lap.Unfold it completely if it is a small napkin,or in half,lengthwise（纵向地）,if it is a large dinner napkin.

If you need to leave the table during the meal,place your napkin on your chair as a signal to your server that you will be returning.Once the meal is over,place your napkin neatly on the table to the right of your dinner plate.Do not refold it.

Use a napkin only for your mouth.Never use it for your nose,face or forehead.

Use of utensils（餐具）

Start with the knife,fork or spoon furthest from your plate,and work your way in,using one utensil for each course.

If soup is served,remember to spoon away from yoursefl.This helps stop the drips.Do not put the entire soup spoon in your mouth.Instead,fill a soup spoon about 75 per cent with soup,and sip（啜饮）it from the side noiselessly.

After finishing dinner,place the knife and fork parallel to one another across the plate with the knife alade facing inward toward the plate.

Using your fingers

Here's a list of finger foods:sandwiches,cookies,small fruits or berries with stems,French fries and potato chips,and hamburgers.

39.All of the following are finger foods except A.soup. B.sandwiches. C.cookies. D.hamburgers.

40.Which of the following shows good table manners? A.Talking with your mouth full. B.Putting bones on your plate. C.Putting your elbows on the table. D.Chewing with your month open.

第三篇

Renewable Energy Sources

Today petroleum（石油）provides around 40% of the world's energy needs,mostly fuelling automobiles.Coal is still used,mostly in power stations,to cover one-quarter of our energy needs,but it is the least efficient,unhealthiest and most environmentally damaging fossil fuel（矿物燃料）.Natural gas reserves could fill some of the gap from oil,but reserves of that will not last into the 22nd century either.Most experts predict we will exhaust easily accessible reserves within 50 years.Less-polluting renewable energy sources offer a more practical long-term energy solution."Renewable"refers to the fact that these resources are not used faster than they can be replaced.

Hydroelectric（水力发电的）power is now the most common form of renewable energy,supplying around 20% of world electricity.China's Three Gorges Dam is the largest ever.At five times the size of the US's Hoover Dam,its 26 turbines（涡轮机）will generate the equivalent energy of 18 coal-fired power stations.It will satisfy 3% of China's entire electricity demand.

In 2003,the first commercial power station to use tidal（潮汐的）currents in the open sea opened in Norway.It is designed like windmill（风车）,but others take the form of turbines.

As prices fall,wind power has become the fastest growing type of electricity generation-quadrupling（翻两番）worldwide between 1999 and 2005.Modern wind farms consist of turbines that generate electricity.Though it will be more expensive,there is more than enough wind to provide the world's entire energy needs.Wind farms come in onshore and offshore forms.They can often end up at spots of natural beauty,and are often unpopular with residents.And turbines are not totally harmless-they can interfere with radar,alter climate and kill sea birds.Scotland is building Europe's largest wind farm,which will power 200,000 homes.The UK's goal is to generate one-fifth of power from renewable sources,mainly wind,by 2020.But this may cause problems,because wind is unreliable.

41.According to the passage,which of the following is the most polluting energy resource? A.Petroleum. B.Coal. C.Natural gas D.Water.

42.China's Three Gorges Dam A.is the first hydroelectric dam in the world. B.is of the same size as the US's Hoover Dam. C.can generate around 3% of world electricity. D.is the largest hydroelectric dam in the world.

43.Which country took the lead in making use of tidal currents to produce power in 2003? A.The UK. B.China. C.Norway. D.The US.

44.One of the problems with wind farms is that A.there is not enough wind. B.wind is not reliable. C.they can only be built on the sea. D.they might influence the world economy.

45.According to the passage,resources like wind are A.renewable. B.recyclable. C.damaging. D.scarce.

Charlotte Hollins knows she faces a battle.The 23-year-old British farmer and her 21-year-old brother Ben are fighting to save the farm from developers that their father worked on since he was 14.（46）

"You don't often get a day off.Supermarkets put a lot of pressure on farmers to keep prices down.With fewer people working on fams it can be isolating,"she said."There is a high rate of suicide and farming will never make you rich!"

Oliver Robinson,25,grew up on a farm in Yorkshire.（47）"I'm sure dad hoped I'd stay,"he said."I guess it's a nice,straightforward life,but it doesn't appeal.For young,ambitious people,farm life would be a hard world."For Robinson,farming doesn't offer much"in terms of money or lifestyle."Hollins agrees that economics stops people from pursuing farming rewards:"providing for a vital human need,while working outdoors with nature."

Farming is a big political issue in the UK.（48）The 2001 foot and mouth crisis closed thousands of farms,stopped meat exports,and raised public consciousness of troubles in UK farming.

Jamie Oliver's 2005 campaign to get children to eat healthily also highlighted the issue.This national concern spells（带来）hope for farmers competing with powerful supermarkets.（49）

A But he never considered staying on his father and grandfather's land. B While most people buy food from the big supermarkets,hundreds of independent Farmers' Markets are becoming popular. C While confident they will succeed,she lists farming's many challenges: D Young people prefer to live in cities. E I seriously objected to the super-sizing of everything-what exactly DO they put on our apples to make them so big and red? F "Buy British"campaigns urge（鼓励）consumers not to buy cheaper imported foods.

第6部分：完形填空（第51~65题，每题1分，共15分） 下面的短文有15处空白，请根据短文内容为每处空白确定1个最佳选项。

An Intelligent Car

Driving needs sharp eyes,keen ears,quick brain,and coordination（协调）between hands and the brain.Many human drivers have all（51）and can control a fast-moving car.But how does an intelligent car control itself?

There is a virtual（虚拟的）driver in the smart car.This virtual driver has"eyes,""brains,""hands"and"feet,"too.The minicameras（52）each side of the car are his"eyes,"which（53）the road conditions ahead of it.They watch the（54）to the car's left and right.There is also a highly automatic driving（55）in the car.It is the built-in computer,which is the virtual driver's"brain."His"brain"（56）the speeds of other moving cars near it and analyzes their positions.Basing on this information,it chooses the（57）path for the intelligent car,and gives instructions to the "hands"and"feet"to act accordingly.In this way,the virtual driver（58）his car.

What is the virtual driver's best advantage?He reacts（59）.The minicameras are bringing（60）continuously to the "brain."It completes the processing of the images within 100 milliseconds.（61）,the world's best driver needs at least one second to react.Besides,when he takes（62）,he needs one more second.

The virtual driver is really wonderful.He can reduce the accident（63）considerably on expressways（高速公路）.In this（64）,can we let him have the wheel at any time and in any place?Experts（65）that we cannot do that just yet.His ability to recognize things is still limited.He can now only drive an intelligent car on expressways.